The invention relates to an image processor which has edit functions and subjects image data obtained by reading a document to edit processes to output the edited image data.
A digital copying machine includes an image input terminal (IIT) for reading a document, an image processing system (IPS) for processing the read image data, and an image output terminal (IOT) for outputting copies while driving, e.g., a laser printer, in accordance with the image data. The image input terminal extracts image data of the document as an analog electric signal corresponding to a reflectance of light using a CCD (charge-coupled device) sensor and converts this electric signal to multi-tone digital image data. The image processing system processes the image data obtained by the image input terminal so that various correcting, converting, and edit operations are performed, while the image output terminal outputs a dotted image by turning on and off a laser of the laser printer in accordance with the image data processed in the image processing system.
Such a digital copying machine produces images in accordance with the type of multi-tone image data through the processing of the image processing system. For example, a binary-coded image such as a character is produced as an edge-enhanced sharp image; a halftone image such as a photograph is outputted as a smooth image; and definition-adjusted, highly reproducible color images can also be outputted. The machine can also produce images that are painted, color-converted, trimmed, shifted, synthesized, reduced, enlarged, and subjected to other edit processes with respect to a document. With respect to the image processing system, the image input terminal reads a document in the form of signals obtained by color-separating the document into the three primary colors, R (red), G (green), and B (blue) and outputs the read image data, while the image output terminal prepares dotted toner images, each corresponding to Y (yellow), M (magenta), C (cyan), or K (black) and outputs these toner images superimposed one upon the other to produce a color image.
An outline of such a color digital copying machine will be described, taking as an example one proposed by the present applicant (e.g., Japanese Patent Unexamined Publication No. Hei. 2-223275). FIG. 4 is a diagram showing an exemplary configuration of a color digital copying machine having conventional edit functions.
In FIG. 4, IIT 100 reads a color document while color-separating it into the three primary colors B, G and R of light using a CCD line sensor and converts the read color document into digital image data; and IOT 115 reproduces the color image by subjecting the image data to an exposing process by a laser beam and to a developing process. Components from equivalent neutral density (END) conversion module 101 to IOT interface 110 interposed between IIT 100 and IOT 115 constitute an image data edit processing system or image processing system (IPS), which converts the image data into Y, M, C, and K to prepare toner signals and outputs to IOT 115 the toner signals, each corresponding to a developing color, every developing cycle.
Further, IIT 100 reads a pixel by the unit of 16 dots/mm for B, G and R using the CCD sensor, and outputs the image data in 24 bits (3 colors.times.8 bits; 256 tone levels). The CCD sensor is covered with filters on its upper surface, each filter corresponding to the primary colors B, G and R. The length of the CCD sensor is 300 mm, and the density thereof is 16 dots/mm. Further, the CCD sensor scans 16 lines/mm at a process speed of 190.5 mm/sec, and therefore the CCD sensor outputs the read data at a speed of approximately 15M pixels/sec every color. IIT 100 converts analog data of B, G and R into logarithmic data to thereby convert the reflectance data into density data, and the density data is further converted into digital data.
The IPS receives color-separated signals for B, G and R from IIT 100, subjects the received signals to various kinds of data processing to improve reproducibility in color, tone, and definition, and outputs toner signals of process colors for development to IOT 115 after converted into on/off signals. END conversion module 101 adjusts or converts the received signals into gray-balanced color signals, and color masking module 102 converts B, G and R signals into toner quantity signals, each corresponding to Y, M, or C by subjecting the B, G and R signals to a matrix calculation. Document size detection module 103 detects the size of the document at the time of prescanning and deletes a platen color (frame) during scanning to read the document. Color conversion module 104 converts a color specified in a predetermined area in accordance with an area signal inputted from an area image control module 111. UCR (under color removal) and black generation module 105 not only generates such an appropriate quantity of K as not to cause "turbidity" in color reproduction to reduce the quantities of Y, M and C commensurate with the quantity of K, but also gates the K signal and the under-color-removed Y, M and C signals in accordance with signals in a monochromatic mode and in a full-color mode. Space filter 106 is a nonlinear digital filter having the function of recovering a dull output and removing moires. Tone reproduction control (TRC) module 107 performs such processing as density and contrast adjustments to improve reproducibility, negative/positive inversion, and color balance adjustment. Reduction/enlargement processing module 108 performs reduction/enlargement processing in the main scanning direction. The reduction/enlargement processing in the auxiliary scanning direction is performed by adjusting a scan speed. Screen generator 109 converts a toner signal in process color into an on/off binary-coded toner signal and outputs the binary-coded toner signal. Such binary-coded toner signal is applied to IOT 115 through IOT interface module 110. Area image control module 111 includes an area generating circuit and a switch matrix, while an edit control module includes area command memory 112, color pallet video switch circuit 113, and font buffer 114, and performs various kinds of edit processing.
The area image control module 111 can set 7 rectangular areas and their priority levels in the area generating circuit, and area control data is set in the switch matrix so as to correspond to each area. The control data include: color conversion; color mode such as monochromatic mode or full color mode; modulation select data such as photograph or character; TRC selection data; and screen generator selection data. These data are used to control the color masking module 102, color conversion module 104, UCR module 105, space filter 106, and TRC module 107. In addition, the switch matrix can be set by software.
The edit control module permits paint processing in which a document such as a graph is read and a specified area thereof whose shape is not limited is painted. A 4-bit area command is written to a plane memory consisting of 4 sheets, so that an edit command corresponding to each point of the document can be set using 4 bits provided by the 4 sheets of plane memory.
In the above color digital copying machine, when making an edit instruction such as color conversion, shading, or painting, its edit content is specified from the console panel, while its edit area is specified either from a document placed on a digitizer or from the console panel based on X and Y coordinates. When the area has been inputted and specified, its position is displayed. To make corrections such as enlarging, reducing, or moving the thus specified edit area, a select screen and a correction screen are called.
In correcting an edit area, a plurality of edit areas and an forward/backward movement key are displayed on the select screen, and a selected area is displayed on the screen, e.g., in reverse. As an area has been selected by operating the forward/backward movement key on the select screen in accordance with a specified sequence, the select screen is switched to the correction screen. On the correction screen, a rectangular area and a correction key such as an arrow or a triangular mark are displayed, with the correction key appearing on each side (upper/lower/right/left) of the rectangular area, and a correction is made to enlarge or reduce the rectangular area by 1 mm in the direction of the arrow or the triangular mark, e.g., every time the correction key is operated.
However, when a document is placed on the digitizer and an area is specified therefrom, the above conventional digital copying machine displays only its position on the display. As a result, an edit content corresponding to the specified area cannot be checked, and its accurate positional relationship with the document cannot be checked.
After edit instructions have been given to a plurality of areas, and even if one area to which a color conversion instruction has been specified is to be checked and corrected based on the checking, the select screen does not indicate the correspondence between the edit area and its edit content. For this reason, the operator must memorize the edit content for each area. Further, to check a specific content, he must obtain a printed copy, which produces copies to be wasted.
To overcome such inconvenience, proposed are a system for displaying the relationship between input data and its programmed recording position (e.g., Japanese Patent Unexamined Publication No. Sho. 63-236063), and a system for displaying image data on a screen to set an area and thereby controlling an output color (e.g., Japanese Patent Unexamined Publication No. Sho. 64-28786). However, these systems do not permit the operator to check the positions and contents of other already specified edit data.